The present application relates generally to detecting arcing in electrical circuits, and more specifically to systems and methods of discriminating between arcing and load-switching noise in direct current (DC) power systems.
In recent years, DC power systems such as photovoltaic (PV) systems have been increasingly employed in home and industrial applications ranging from charging batteries to supplying power to the alternating current (AC) grid. Such PV systems can include a plurality of PV modules (e.g., solar panels) serially connected to form one or more PV strings. Multiple PV strings can be connected in parallel, and routed through a combiner box for ultimately driving a charger or inverter load. In a typical PV system, each PV module can be configured to generate a current output of up to about 10 amps at 50 Vdc, and each PV string can be configured to produce a voltage output of up to about 1000 Vdc or more, depending on the number of PV modules connected on the PV string. Further, the PV strings connected in parallel can be configured to boost the total current output of the typical PV system up to about 200 amps or more.
Because DC power systems such as the PV systems described above can be configured to generate relatively high current and voltage outputs, there is a need for systems and methods of detecting arcing in such power systems. For example, in the typical PV system, in which the current output and the voltage output can be on the order of 200 amps and 1000 Vdc, respectively, series arcing can be produced by disconnecting PV power cables, parallel arcing can be produced by shorting the PV power cables, and ground fault arcing can be produced by shorting the PV power cables to ground. However, known systems and methods of detecting arcing in power systems have heretofore been generally incapable of differentiating between series arcing, parallel arcing, ground fault arcing, etc., and noise generated by charger loads, inverter loads, DC-to-DC load-switching, DC-to-AC load-switching, DC disconnect switches, radio frequency (RF) pickup, DC power line communications, etc., with a high level of reliability.